c# - C# で動画ファイルのサムネイル画像を取得する

Question

自分のサイトにリストされている動画のサムネイルを表示したい。動画から (特定の時間から) 1 つのフレームを取得して、それらをサムネイルとして表示したい。

http://ramcrishna.blogspot.com/2008/09/playing-videos-like-youtube-and.htmlを試しましたが、機能しません。

.NET C# を使用してそれは可能ですか?

Answer 1

プログラムでFFmpegを実行して、サムネイル画像ファイルを生成できます。次に、画像ファイルを開いて、必要に応じて使用します。

サンプルコードは次のとおりです。

public static Bitmap GetThumbnail(string video, string thumbnail)
{
    var cmd = "ffmpeg  -itsoffset -1  -i " + '"' + video + '"' + " -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 " + '"' + thumbnail + '"';

    var startInfo = new ProcessStartInfo
    {
        WindowStyle = ProcessWindowStyle.Hidden,
        FileName = "cmd.exe",
        Arguments = "/C " + cmd
    };

    var process = new Process
    {
        StartInfo = startInfo
    };

    process.Start();
    process.WaitForExit(5000);

    return LoadImage(thumbnail);
}

static Bitmap LoadImage(string path)
{
    var ms = new MemoryStream(File.ReadAllBytes(path));
    return (Bitmap)Image.FromStream(ms);
}

Answer 2

 [HttpPost]
        [Route("UploadImages")]
        public HttpResponseMessage Post()
        {
            HttpResponseMessage response = new HttpResponseMessage();
            var httpRequest = HttpContext.Current.Request;
            if (httpRequest.Files.Count > 0)
            {
                var docfiles = new List<string>();
                foreach (string file in httpRequest.Files)
                {
                    var postedFile = httpRequest.Files[file];
                    var filePath1 = HttpContext.Current.Server.MapPath("~/ImgFolder/" + postedFile.FileName);

                    Stream strm = postedFile.InputStream;

                    CreateThumbnail(strm, postedFile.FileName);

                    Compressimage(strm, filePath1, postedFile.FileName);


                }
                response = Request.CreateResponse(HttpStatusCode.Created, docfiles);
            }
            else
            {
                response = Request.CreateResponse(HttpStatusCode.BadRequest);
            }
            return response;
        }
        public static void **CreateThumbnail**(Stream sourcePath, string filename)
        {
            Image image = Image.FromStream(sourcePath);
            Image thumb = image.GetThumbnailImage(120, 120, () => false, IntPtr.Zero);
             var filePath1 = HttpContext.Current.Server.MapPath("~/Thumbnail/" + filename);

             thumb.Save(filePath1 + filename);

        }

        public static void Compressimage(Stream sourcePath, string targetPath, String filename)  
        {  


            try  
            {  
                using (var image = Image.FromStream(sourcePath))  
                {  
                    float maxHeight = 900.0f;  
                    float maxWidth = 900.0f;  
                    int newWidth;  
                    int newHeight;  
                    string extension;  
                    Bitmap originalBMP = new Bitmap(sourcePath);  
                    int originalWidth = originalBMP.Width;  
                    int originalHeight = originalBMP.Height;  

                    if (originalWidth > maxWidth || originalHeight > maxHeight)  
                    {  

                        // To preserve the aspect ratio  
                        float ratioX = (float)maxWidth / (float)originalWidth;  
                        float ratioY = (float)maxHeight / (float)originalHeight;  
                        float ratio = Math.Min(ratioX, ratioY);  
                        newWidth = (int)(originalWidth * ratio);  
                        newHeight = (int)(originalHeight * ratio);  
                    }  
                    else  
                    {  
                        newWidth = (int)originalWidth;  
                        newHeight = (int)originalHeight;  

                    }  
                    Bitmap bitMAP1 = new Bitmap(originalBMP, newWidth, newHeight);  
                    Graphics imgGraph = Graphics.FromImage(bitMAP1);  
                    extension = Path.GetExtension(targetPath);  
                    if (extension == ".png" || extension == ".gif")  
                    {  
                        imgGraph.SmoothingMode = SmoothingMode.AntiAlias;  
                        imgGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;  
                        imgGraph.DrawImage(originalBMP, 0, 0, newWidth, newHeight);  


                        bitMAP1.Save(targetPath, image.RawFormat);  

                        bitMAP1.Dispose();  
                        imgGraph.Dispose();  
                        originalBMP.Dispose();  
                    }  
                    else if (extension == ".jpg")  
                    {  

                        imgGraph.SmoothingMode = SmoothingMode.AntiAlias;  
                        imgGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;  
                        imgGraph.DrawImage(originalBMP, 0, 0, newWidth, newHeight);  
                        ImageCodecInfo jpgEncoder = GetEncoder(ImageFormat.Jpeg);  
                        Encoder myEncoder = Encoder.Quality;  
                        EncoderParameters myEncoderParameters = new EncoderParameters(1);  
                        EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 50L);  
                        myEncoderParameters.Param[0] = myEncoderParameter;  
                        bitMAP1.Save(targetPath, jpgEncoder, myEncoderParameters);  

                        bitMAP1.Dispose();  
                        imgGraph.Dispose();  
                        originalBMP.Dispose();  

                    }  


                }  

            }  
            catch (Exception)  
            {  
                throw;  

            }  
        }  


        public static ImageCodecInfo GetEncoder(ImageFormat format)  
        {  

            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();  

            foreach (ImageCodecInfo codec in codecs)  
            {  
                if (codec.FormatID == format.Guid)  
                {  
                    return codec;  
                }  
            }  
            return null;  
        }